edu.ucar.opensky::articles:26123 UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact 2025-12-24T19:40:14.771014 ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data ISO 19115-2:2009(E) https://n2t.org/ark:/85065/d7q2445r https://doi.org/10.15138/yaf1-bk21 https Related Dataset #1 NOAA Global Monitoring Laboratory Carbon Cycle and Greenhouse Gases Group Continuous Insitu Measurements of CO2 at Global Background Sites, 1973-Present https://doi.org/10.22033/ESGF/CMIP6.10071 https Related Dataset #2 NCAR CESM2-WACCM model output prepared for CMIP6 CMIP historical https://doi.org/10.22033/ESGF/CMIP6.10894 https Related Dataset #3 NCC NorCPM1 model output prepared for CMIP6 CMIP historical https://doi.org/10.22033/ESGF/CMIP6.11297 https Related Dataset #4 NCAR CESM2-FV2 model output prepared for CMIP6 CMIP historical https://doi.org/10.22033/ESGF/CMIP6.11298 https Related Dataset #5 NCAR CESM2-WACCM-FV2 model output prepared for CMIP6 CMIP historical https://doi.org/10.22033/ESGF/CMIP6.13195 https Related Dataset #6 CMCC CMCC-ESM2 model output prepared for CMIP6 CMIP historical https://doi.org/10.22033/ESGF/CMIP6.3610 https Related Dataset #7 CCCma CanESM5 model output prepared for CMIP6 CMIP historical https://doi.org/10.22033/ESGF/CMIP6.3825 https Related Dataset #8 CMCC CMCC-CM2-SR5 model output prepared for CMIP6 CMIP historical https://doi.org/10.22033/ESGF/CMIP6.4272 https Related Dataset #9 CSIRO ACCESS-ESM1.5 model output prepared for CMIP6 CMIP historical https://doi.org/10.22033/ESGF/CMIP6.5016 https Related Dataset #10 HAMMOZ-Consortium MPI-ESM1.2-HAM model output prepared for CMIP6 CMIP historical https://doi.org/10.22033/ESGF/CMIP6.5195 https Related Dataset #11 IPSL IPSL-CM6A-LR model output prepared for CMIP6 CMIP historical https://doi.org/10.22033/ESGF/CMIP6.6595 https Related Dataset #12 MPI-M MPI-ESM1.2-LR model output prepared for CMIP6 CMIP historical https://doi.org/10.22033/ESGF/CMIP6.7127 https Related Dataset #13 NASA-GISS GISS-E2.1G model output prepared for CMIP6 CMIP historical https://doi.org/10.22033/ESGF/CMIP6.7128 https Related Dataset #14 NASA-GISS GISS-E2.1H model output prepared for CMIP6 CMIP historical https://doi.org/10.22033/ESGF/CMIP6.7627 https Related Dataset #15 NCAR CESM2 model output prepared for CMIP6 CMIP historical https://doi.org/10.22033/ESGF/CMIP6.8036 https Related Dataset #16 NCC NorESM2-LM model output prepared for CMIP6 CMIP historical https://doi.org/10.22033/ESGF/CMIP6.8040 https Related Dataset #17 NCC NorESM2-MM model output prepared for CMIP6 CMIP historical https://doi.org/10.22033/ESGF/CMIP6.9755 https Related Dataset #18 AS-RCEC TaiESM1.0 model output prepared for CMIP6 CMIP historical https://doi.org/10.3334/ORNLDAAC/1925 https Related Dataset #19 ATom: Merged Atmospheric Chemistry, Trace Gases, and Aerosols, Version 2 https://doi.org/10.5281/zenodo.5776197 https Related Dataset #20 MIROC4-ACTM CO2 Inversion flux (2001-2020; case s050_ux4_gc3t) https://doi.org/10.25925/20201008 https Related Software #1 CarbonTracker CT2019B Evaluating Northern Hemisphere growing season net carbon flux in climate models using aircraft observations 2023-02-01T00:00:00Z publication https://n2t.org/ark:/85065/d7q2445r https://doi.org/10.1029/2022GB007520 Loechli, M. author Stephens, Britton author Commane, R. author Chevallier, F. author McKain, K. author Keeling, R. F. author Morgan, E. J. author Patra, P. K. author Sargent, M. R. author Sweeney, C. author Keppel-Aleks, G. author UCAR/NCAR - Library publisher Understanding terrestrial ecosystems and their response to anthropogenic climate change requires quantification of land-atmosphere carbon exchange. However, top-down and bottom-up estimates of large-scale land-atmosphere fluxes, including the northern extratropical growing season net flux (GSNF), show significant discrepancies. We developed a data-driven metric for the GSNF using atmospheric carbon dioxide concentration observations collected during the High-Performance Instrumented Airborne Platform for Environmental Research Pole-to-Pole Observations and Atmospheric Tomography Mission flight campaigns. This aircraft-derived metric is bias-corrected using three independent atmospheric inversion systems. We estimate the northern extratropical GSNF to be 5.7 +/- 0.3 Pg C and use it to evaluate net biosphere productivity from the Coupled Model Intercomparison Project phase 5 and 6 (CMIP5 and CMIP6) models. While the model-to-model spread in the GSNF has decreased in the CMIP6 models relative to that of the CMIP5 models, there is still disagreement on the magnitude and timing of seasonal carbon uptake with most models underestimating the GSNF and overestimating the length of the growing season relative to the observations. We also use an emergent constraint approach to estimate annual northern extratropical gross primary productivity to be 56 +/- 17 Pg C, heterotrophic respiration to be 25 +/- 13 Pg C, and net primary productivity to be 28 +/- 12 Pg C. The flux inferred from these aircraft observations provides an additional constraint on large-scale gross fluxes in prognostic Earth system models that may ultimately improve our ability to accurately predict carbon-climate feedbacks.Plain Language Summary The exchange of carbon between the land and atmosphere is an important part of the Earth's climate, and this exchange might change due to human-caused climate change. However, estimates of land-atmosphere carbon fluxes made using different techniques do not agree with each other. We use atmospheric carbon dioxide observations collected during two flight campaigns to show that 5.7 Pg C is exchanged between the atmosphere and the land in the northern hemisphere during the summer growing season. This estimate is used to evaluate the performance of two generations of climate prediction models. The newer generation of models show less spread than the older generation, but there is still significant disagreement on the magnitude and timing of land-atmosphere carbon exchange among models. Most models underestimate the growing season net flux and overestimate the length of the growing season. We also use our observational estimate to reduce the spread on component fluxes of carbon exchange, namely uptake by photosynthesis and release by respiration. UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact PDF Text theme Resource Type 2016-01-01T00:00:00Z publication Copyright author(s). This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License. None eng geoscientificInformation